Apparatus for levelling, smoothing, and grading snow

ABSTRACT

A device is disclosed for use with a vehicle, preferably of the track laying type which is adaptable for traversing, under low bearing pressure conditions, areas and surfaces of snow, mud, sand and other off-highway media of low density, which by virtue of its unique construction and association with the vehicle, enhances remarkably the steering capability thereof. Further, when used on a vehicle which is equipped with a grading plow for grading the surfaces being traversed, enhances the capability of the vehicle to perform grading and leveling operations with great precision not heretofore possible. The device comprises a boomlike frame mounted on the front of the vehicle and formed so as to extend over and above the grading plow and terminating in a steering ski at a point substantially forwardly of the vehicle. The ski, adjustably hinged to the boom-frame, is capable of (1) being raised above the surface being traversed (2) maintaining sliding contact therewith and (3) transmitting a downward force supplied by a control means connecting the boom-frame to the vehicle.

United States atent Eskelson et al.

[15] ,656,557 Apr. 1, W72

[72] Inventors: Ross W. Eskelson, Smithfield; James S.

Johnson, Logan, both of Utah [73] Assignee: Thiokol Chemical Corporation, Bristol, Pa. [22] Filed: Aug. 12, 1969 [21] Appl. No.: 849,403

2,846,017 8/1958 Luchterhand I ..280/28 3,027,662 4/1962 Cunningham... ...l72/277 X 3,166,338 l/l965 Romsdal ......280/21 Primary Examiner-Robert E. Pulfrey Assistant Examiner-Stephen C. Pellegrino Attorney-Thomas W. Brennan [5 7] ABSTRACT A device is disclosed for use with a vehicle, preferably of the track laying type which is adaptable for traversing, under low bearing pressure conditions, areas and surfaces of snow, mud, sand and other off-highway media of low density, which by virtue of its unique construction and association with the vehicle, enhances remarkably the steering capability thereof. Further, when used on a vehicle which is equipped with a grading plow for grading the surfaces being traversed, enhances the capability of the vehicle to perfomi grading and leveling operations with great precision not heretofore possible. The device comprises a boom-like frame mounted on the front of the vehicle and formed so as to extend over and above the grading plow and terminating in a steering ski at a point substantially forwardly of the vehicle. The ski, adjustably hinged to the boomframe, is capable of (1) being raised above the surface being traversed (2) maintaining sliding contact therewith and (3) transmitting a downward force supplied by a control means connecting the boom-frame to the vehicle.

5 Claims, 4 Drawing Figures PATENTEDAPRmIQR sum lflF 3 Ross W Es/re/son James 5. Johnson I NVENTORS PATENTEDAPRIBIQIZ 3556,55?

sum 2 OF 3 Ross WE's/re/son James .S. Johnson INVENTORS PATENTEDAPR 1 8 I972 8, 6 56. 5 57 Ross W Es/re/son James S. Johnson INVENTORS BACKGROUND OF THE INVENTION In the art of vehicles utilized for traversing surfaces such as soft snow, mud, sand and other low density media, which are capable of supporting only low pressure bearing loads, it has often-times been found impossible to prepare and maintain these surfaces and render them level and smooth because of the vehicle imposed loads and bearing pressures generated. Present day machines being used are usually of the so-called track laying type being equipped with a movable plow or blade mounted in front thereof. However, such vehicles though capable of exerting low forces and bearing pressures and therefore supportable on soft surfaces, usually push the plow to grade the surface. In such instances as plowing by pushing the controllable blade, it is close to impossible to maintain a precise posture of the blade relative to the surface for sustained periods; especially over relatively large areas because of the oscillatory, i.e., up and down motion of the prime mover or track-laying machine.

Other devices, such as the well known earth moving or grading machine, which moves on low pressure pneumatic tired wheels with the plow or grading blade positioned between the front steering and rear wheels, the front wheels being attached to a frame extending a considerable distance forward of the main vehicle body, generally operate well, but only on a surface sufficiently compacted to support their relatively larger weights and pressures. Efforts have been made to adapt such vehicles by means of removable tracks on belts having cleated elements so as to disperse the vehicle weight over larger areas, thereby permitting the vehicle to traverse snow areas and other soft surfaces. However, other problems have been encountered in adapting these vehicles for such use, which problems have been substantially solved, as will become evident from the description of the herein presented invention. In general, the present invention is a unique addition to the art of grading, clearing and leveling, for example, snow covered slopes and hills such as are found in ski resorts. In these areas it is of great importance to remove certain types of icy formations known as moguls formed by skiers on the skis trails, at points where turns are repeatedly made. It is important to be able to quickly smooth out, remove or crush these moguls to remove what would otherwise be dangerous hazards to the skier because of loss of ski traction should he unexpectedly come upon one.

SUMMARY OF THE INVENTION This invention relates to vehicles, preferably of the track laying type, which are equipped with snow plow devices or other means for performing grading and scraping operations, and which are further provided with means such as the cleated track for traversal of surfaces in areas where high bearing pressures cannot be supported. More particularly, the invention relates to vehicles of the type above indicated wherein a steering ski is mounted on the end of an elongated boom or frame, which is attached at its other end to the front end of the vehicle; and further wherein the boom or frame is controllable in elevation by power means.

By use of the invention above referredto, a track laying vehicle fitted with an endless cleated track such as disclosed in US. No. 3,165,364 to R. W. Eskelson et al., and which is a low bearing pressure vehicle, is rendered capable of performing work and other operations in conjunction with grading of the surfaces referred to in a rather surprising and unique way. Further, use of the ski which in its preferred embodiment is steerable from the vehicle operator position, and, through suitable control means attached to the boom, is capable of transmitting a downward force to the surface, whereby the vehicle weight, or a substantial portion thereof is distributed so as to be suspended between the ski and rear of the vehicle. By this means, as will be indicated more fully in what follows,

the tracks by means of a so called joy stick" control to obtain a differential speed therebetween to turn the vehicle is more easily accomplished and with less power expenditure. Thus, I

the driver is freed to concentrate on operating other equipment since he will be relieved of much of the difficulty of steering, even to the extent of accomplishing this with one hand. In addition, engine power is conserved since none must be sacrificed to the brake and turn operations required in the usual prior art type vehicle and plow arrangement. This, as will become more apparant, is particularly advantageous wherein ski slopes and other very uneven surfaces must be prepared and maintained.

Accordingly, it is an important object of this invention to provide a novel vehicle in combination with a forwardly extending boom or frame having a steerable ski means at the end thereof, which thereby possesses enhanced capabilities of steering and/or grading or leveling operations required to be performed in maintaining areas having surfaces capable of supporting only low bearing pressures.

Another object of this invention is to provide a vehicle of the character, described wherein grading operations performed by such vehicles on surfaces capable of supporting only low bearing pressure is accomplished with greater precision than heretofore possible.

Still another object of this invention is to provide a vehicle combination as above described wherein the steering capability thereof is enhanced through reducing the effort required by the operator of the vehicle in performing such operations.

With the above and other objects and advantages in mind, as will appear to those skilled in the art, the invention comprises a vehicle, preferably of the track laying type, having an elongated means attached to the front end thereof and extending therefrom a substantial distance to a steerable, ground contacting means attached thereto whereby the vehicle, in combination with said elongated means and other attachments ordinarily found in such vehicles, accomplishes its usual task in greater precision, greater speed, more economically and with far less expenditure of effort by the operator.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial, front elevational view of the invention showing a grading plow or blade and attachment of the elongated boom;

FIG. 2 is a view similar to FIG. 1 but viewed from a point in front and partially broken away to shown some of the detail P FIG. 3 is a pictorial view of the invention illustrating it operating on a snow or ski slope; and,

FIG. 4 is a top view of a detail of the invention.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, and in particular to FIG. 1, there is shown a vehicle 10 of the track-laying type. Attached to vehicle 10 by means of a mounting frame 11 comprising a vertical, or upper portion ll-a and a horizontal, or lower portion ll-b, the latter extending under vehicle 10 for attachment thereto at a convenient place (not shown), is a grading plow assembly 12 for grading, scraping, or levelling snow and the like. Plow 12 is attached to vehicle 10 through horitzontally extending frame or plate 1 l-c which by connection thereof to portion ll-b by pin connectors 13-0 (one only shown) is capable of being rotated thereabout. A pair of horizontal power cylinders 13 are mounted between plate 11-0 and plow 12, said power cylinders 13 being selectively operated to effect a push and pull motion on plow 12 and thereby rotate same about a vertical axis through a forwardly positioned plate pin 13-h. An additional power cylinder 13-c is mounted above and between cylinders 13 through suitable pin connections to frame 11 upper portion 111: and to plate ll-c, thereby enabling raising and lowering, i.e., rotating, plow l2 and plate ll-c about connection pins 13-0. Thus it is seen that cylinders steering, which ordinarily is accomplished by braking one of 13, when operated in push-pull fashion permit rotation of plow 12 about a vertical axis through pin 13-b to provide angular control of plow 12, whereas ylinder 13-0 permits plow 12 to be raised and lowered, i.e., elevational control of plow 12 is obtained thereby, being rotatable, as stated above, about pin connectors l3-c, although its upward movement is seen to be limited by gusset plate connectors of a forwardly extending angular boom 15 to be later described. An additional power cylinder 14, is mounted on plow 12 to permit rotational control of plow 12 about a horizontal, or longitudinal axis. Therefore, by selectively supplying hydraulic, or if desired pneumatic pressure to the appropriate power cylinder 13, l3-a or 14, plow 12 can be raised, lowered, turned in or out, or up or down, thereby performing various levelling or grading operations all under complete control of the vehicle operator. It should therefore be evident that these unique control features of this invention result in a marked improvement and provide those artisens in the art concerned, with a highly useful tool.

Attached to frame 11 by means of suitable pin connectors and gussets or the like, as noted above, is angular boom-like structure or frame 15, which because of the pin connection thereto is rotatable thereabout. A power cylinder 15-a mounted on upper frame piece ll-a and a structural member of frame 15, permits limited rotation thereof about frame 11 pin connectors as shown in the drawings.

Boom or frame 15 is fabricated of structural steel and is of angular configuration, to permit more effective action by attached power cylinder 15-11, and is comprised of two main sections; a short rear section 16 having suitable fittings for pin connecting it to vehicle on frame piece 11-0 and which terminates in an angular gusset plate 17; and a longer, forward section 18, which extends from gusset l7 forwardly subtending an obtuse angle therebetween. Longer section 18 terminates in a steering ski 19, which, as shown in FIG. 2 hinges on a pin 20 to freely rotate thereabout; but which is steerable by means of a power cylinder 21 operating a crank arm 22, indicated by the arrows in FIG. 4. For clarity, in all of the illustrations, it should be noted, all hydraulic and/or pneumatic pressure lines and hoses have been eliminated. Also, as shown in FIG. 2 cylinder 21 is connected to the end of boom, or frame through a bracket welded to a longitudinal structural member thereof. An additional pin 23 passes through arm 22, being connected thereto for rotation therewith by well known means, for example a woodruff key indicated in FIG. 4. And, fixed to the bottom surface of ski 19 is a keel 24 which extends along the surface thereat in the central portion thereof.

In exemplification of the hereinabove described invention, operation thereof on snow covered surfaces is described, since in such surfaces, uneven areas, which often-times present dangerous obstacles to skiers or other who find it necessary to travel in such areas, are often encountered. It is, of course, important to operators and proprietors of ski lodges and the like, to be able to prepare and groom their ski slopes and trails to clear them of icy, or hard packed snow formations commonly referred to as moguls, which present hazards to skiers, because they are formed at turning points in the trails.

In order, however, to remove or break-up these undesirable formations, it is, of course, necessary to traverse these soft or loosely compacted surfaces with reasonable speed and traction. Commonly, track laying vehicles such as vehicle 10, are employed, since they are known to exert very low ground pressure, and which can be readily equipped with snow plows or graders 12 to remove moguls and similar unwanted surface defects. However, it has been found that the vehicle and plow arrangement alone do not always satisfactorily accomplish the desired result because of the cantilever type loads resulting by forwardly positioning plow 12. This causes vehicle 10 and plow l2 combination to rock fore and aft, complicating the plowing or grading operation. Attempts to lessen this effect by pulling heavy drum packers or other devices behind the vehicle, have not proved satisfactory, especially on the steeper slopes and hills.

In contrast, it has been found, by use of the herein disclosed inventive boom or frame 15 attachment to the frame of vehicle 10 as described, several surprising and pleasing effects are obtained. Firstly, boom 15 can be raised above the surface, adjusted to merely slidably contact the surface, or bear against the surface through steerable ski 19 by means of power cylinder 15-0. With steerable ski 19 being forced downwardly into the surface, steering of the entire vehicle system can be achieved by the operator. Secondly, by means of boom 15 and sliding ski 19, the effective length of vehicle 10 is increased, hence fore and aft rocking is practically eliminated. Thirdly, plow 12, because ski 19 in performing as a steering platform floats along the surface under controlled conditions with keel 24 permitting side loads for steering, removes high ridges and fills in low areas to provide a level surface for vehicle 10 to move in. Simultaneously, the prime mover on vehicle 10 retains its capability of traversing soft or low density surfaces under very low load bearing conditions. Lastly snow plowing to break new trails in new snow is more easily and economically accomplished, enhanced in precision, and effectiveness, and without over-loading plow 12.

As noted above, use of ski 19 in conjunction with vehicle 10 and plow 12, with proper application of force to ski 19, grading capability is greatly enhanced. Further, ski 19 is steerable from the vehicle by means of cylinder 21, and since it gains side loading because of its keel 24, it has been found that the usual manner of steering by braking each track is unnecessary. This in turns permits vehicle 10 engine power to be more efficiently utilized in propelling the vehicle. Thus when traversing steep slopes, and especially in maneuvering thereon, overall vehicle performance is greatly enhanced.

Therefore, what has been added to the art of low pressure bearing vehicles and related equipment is a new combination of a vehicle, particularly of the track laying type which permits better maintenance and preparation of low density surfaces capable only of supporting low bearing pressures, so that grading, clearing and leveling can be easily and more economically accomplished.

What is claimed is:

1. In a track-laying vehicle for traversing snow surfaces and the like, said vehicle equipped with snow-grading, surface smoothing accessory means and being self propelled and further including power cylinders for raising and lowering the grading and smoothing means, the improvement comprising, in combination:

an elongated boom frame hingeably attached to the front of said vehicle at one of its ends;

hydraulic power means mounted on said vehicle and attached to said boom frame for raising and lowering said frame and applying through said frame a downward force at the front end thereof;

a steerable ski pivotally attached to the forward end of said frame and adapted to slidably move over the surface when propelled by said track-laying vehicle, said ski providing ground support for said downward force applied by said raising and lowering power means on said vehicle;

additional power means mounted on said frame and attached to said ski for steering said ski and said vehicle; and,

said boom frame comprising a first section including pivotal attaching means to said vehicle and extending angularly upward therefrom and a second section connected to said first section and extending downwardly therefrom to subtend an obtuse angle therebetween.

2. The invention according to claim 1 wherein the means for steering said ski is a power cylinder.

3. The vehicle of claim 1 wherein said ski further includes a keel-like element attached to the bottom side thereof side thereof for penetrating the surface being traversed while sliding thereover.

4. The vehicle according to claim 1 wherein the means for lowering and raising said beam is a power cylinder.

5. The invention according to claim 1 wherein the boomlike frame forms an obtuse angle directed with respect to said vehicle and said ski so as to have a short side of said angle extending upwardly from said vehicle attachment point in the front thereof, and a long side of said angle extending to said 5 steering ski. 

1. In a track-laying vehicle for traversing snow surfaces and the like, said vehicle equipped with snow-grading, surface smoothing accessory means and being self propelled and further including power cylinders for raising and lowering the grading and smoothing means, the improvement comprising, in combination: an elongated boom frame hingeably attached to the front of said vehicle at one of its ends; hydraulic power means mounted on said vehicle and attached to said boom frame for raising and lowering said frame and applying through said frame a downward force at the front end thereof; a steerable ski pivotally attached to the forward end of said frame and adapted to slidably move over the surface when propelled by said track-laying vehicle, said ski providing ground support for said downward force applied by said raising and lowering power means on said vehicle; additional power means mounted on said frame and attached to said ski for steering said ski and said vehicle; and, said boom frame comprising a first section including pivotal attaching means to said vehicle and extending angularly upward therefrom and a second section connected to said first section and extending downwardly therefrom to subtend an obtuse angle therebetween.
 2. The invention according to claim 1 wherein the means for steering said ski is a power cylinder.
 3. The vehicle of claim 1 wherein said ski further includes a keel-like element attached to the bottom side thereof for penetrating the surface being traversed while sliding thereover.
 4. The vehicle according to claim 1 wherein the means for lowering and raising said beam is a power cylinder.
 5. The invention according to claim 1 wherein the boom-like frame forms an obtuse angle directed with respect to said vehicle and said ski so as to have a short side of said angle extending upwardly from said vehicle attachment point in the front thereof, and a long side of said angle extending to said steering ski. 